The men's 400 metre freestyle competition of the swimming events at the 2013 Mediterranean Games took place on June 21 at the Mersin Olympic Swimming Pool in Mersin, Turkey.^[1] Oussama Mellouli of Tunisia was the defending champion from the 2009 Mediterranean Games.

This article includes a list of general references, but it lacks sufficient corresponding inline citations. (December 2013)

This race consisted of eight lengths of the pool in freestyle.

All times are Eastern European Summer Time (UTC+03:00)

Prior to this competition, the existing world and Mediterranean Games records were as follows:

World record	Paul Biedermann (GER)	3:40.07	Rome, Italy	July 26, 2009
Mediterranean Games record	Oussama Mellouli (TUN)	3:42.71	Pescara, Italy	June 27, 2009